- Dust and Plasma Wave Phenomena
- Ionosphere and magnetosphere dynamics
- Magnetic confinement fusion research
- High-pressure geophysics and materials
- Nonlinear Waves and Solitons
- Nonlinear Photonic Systems
- Astro and Planetary Science
- Solar and Space Plasma Dynamics
- Earthquake Detection and Analysis
- Streptococcal Infections and Treatments
- Geomagnetism and Paleomagnetism Studies
- Laser-Plasma Interactions and Diagnostics
- Geophysics and Gravity Measurements
- Fluid Dynamics and Turbulent Flows
- Cold Atom Physics and Bose-Einstein Condensates
- Atomic and Molecular Physics
Abdus Salam Centre for Physics
2012-2025
Quaid-i-Azam University
2008-2025
Multi-soliton interaction of nonlinear ion sound waves in a pair-ion–electron (PIE) plasma having non-Maxwellian electrons including Kappa, Cairns, and generalized two spectral index distribution functions is studied. To this end, modified Korteweg–de Vries (mKdV) equation obtained to investigate the ion-acoustic PIE at critical composition. The effects temperature density ratios electron velocity distributions on overtaking solitons are explored detail. results reveal that both hump...
Linear and nonlinear acoustic drift waves in a confined inhomogeneous dusty plasma are investigated here. We examine two distinct scenarios that correspond to slow fast temporal dynamics. The dust particles inert the first scenario, but actively participate dynamics second. Accordingly, we distinguish between coupled dust-modified ion-acoustic ultra-low-frequency waves. corresponding dispersion relations were determined both situations by using linear analysis. In addition, coherent...
The observations of the magnetospheric multiscale (MMS) and Cassini Huygen's missions report presence cold hot populations electrons, which lead to generation electron-acoustic waves. observed electron velocity distributions from these demonstrate that particles do not follow Maxwellian distribution, exhibit distinct characteristics, can be effectively accounted for by other non-Maxwellian distributions. Motivated observations, we investigate nonlinear solitary waves (EASWs) in a cylindrical...
Complicated wave behavior observed in the cylindrical pair-ion (fullerene) experiments by Oohara and co-workers are now identified to be low harmonic ion cyclotron waves combined with plasma oscillations inherent kinetic theory. The electrostatic dispersion equation derived is based on an approximation for current from exact solutions of characteristic geometry form Vlasov a uniform magnetized cylinder surrounded larger metal boundary outside vacuum gap, which thus differs that unbounded...
The Korteweg–de Vries–Burgers equation is derived for drift waves in a partially ionized nonuniform pair-ion-electron (PIE) plasma. nonlinearity appears due to electron temperature gradient. analytical solutions the form of solitons, monotonic shocks, and oscillatory shocks have been obtained. numerical calculations also presented PIE plasmas fullerene hydrogen illustration keeping view recent experiments. This work can be useful future experimental investigations.
The effects of nonthermal electron distributions on electrostatic ion-temperature-gradient (ITG) driven drift-wave instabilities in the presence equilibrium density, temperature, and magnetic field gradients are investigated here. By using Braginskii’s transport equations for ions Cairns as well Kappa distribution electrons, coupled mode derived. modified ITG modes derived, it is found both analytically numerically that electrons significantly modify real frequencies growth rate drift wave...
One dimensional propagation of fast magnetoacoustic solitary waves in dense plasmas with degenerate electrons is investigated this paper the small amplitude limit. In regard, Korteweg deVries equation derived and discussed using plasma parameters that are typically found white dwarf stars. The interaction solitons explored by Hirota bilinear formalism, which admits multi soliton solutions. It observed values vectors determine waves. further noted respective remain unchanged after...
Nonlinear equations which govern the dynamics of low-frequency toroidal ion-temperature-gradient driven modes (i.e., ω≪ωci, where ωci is ion gyro-frequency) are derived in presence equilibrium density, temperature, and magnetic field gradients. In nonlinear case, solutions form dipolar vortices vortex street presented for a plasma comprising Maxwellian ions nonthermal electrons that embedded an external field. By using Braginskii's transport Kappa distributed electrons, coupled mode system...
In the present investigation, cylindrical Kadomstev-Petviashvili (CKP) equation is derived in pair-ion-electron plasmas to study propagation and interaction of two solitons. Using a novel gauge transformation, soliton solutions CKP are found analytically by using Hirota's method best our knowledge have been used plasma physics for first time. Interestingly, it observed that unlike planar (KP) equation, admits horseshoe-like solitary structures. Another non-trivial feature solution parameter...
We study here the nonlinear oblique propagation of magnetoacoustic waves in dense plasmas with degenerate electrons by deriving Kadomtsev-Petviashvili (KP) equation for small but finite amplitude perturbations. The two soliton interaction has been studied finding solution KP using Hirota bilinear formalism. For illustrative purposes, we have used plasma parameters typically found white dwarf stars both fast and slow modes waves. It observed that is strongly influenced predominant weak...
We derive the nonlinear equations governing dynamics of three-dimensional (3D) disturbances in a nonuniform rotating self-gravitating fluid under assumption that characteristic frequencies are small compared to rotation frequency. Analytical solutions these found form 3D vortex dipole solitons. The method for obtaining is based on well-known Larichev-Reznik procedure finding two-dimensional physics atmospheres planets. In addition basic x-antisymmetric part (carrier), solution may also...
The shear flow-driven electrostatic instabilities are investigated in ideal low density, temperature pair-ion-electron and pure pair-ion plasmas several different cases, including homogeneous inhomogeneous density effects. In uniform plasma, when the flow is of order acoustic speed, purely growing D’Angelo mode can give rise to fields. case an drift wave becomes unstable. presence negative ions, however, reduces growth rate. If positive ions not thermal equilibrium with each other, then also...
In this paper, we have investigated the ion temperature gradient (ITG) driven electrostatic drift waves in presence of non-thermal electrons that follow generalized (r, q) distribution. linear regime, derived dispersion relation coupled drift-ion acoustic wave. nonlinear stationary solutions equations been obtained gradients equilibrium density, and magnetic field. It has found tail parameter q flatness r strongly affect profiles non-linear propagation characteristics ITG waves. flat-topped...
The cylindrical Kadomtsev-Petviashvili (CKP) equation, also known as Johnson's is derived for dense electron ion plasmas in the small amplitude limit to study interaction and resonance of two magnetoacoustic solitons geometry. exact analytical solutions CKP equation are using Hirota's direct method a novel gauge transformation. It observed that geometry transforms line horseshoe-like solitary structures. For multi-solitons, it shown parameter wave depends upon plasma parameters system....
Backward waves observed in the experiments by Oohara and Hatakeyama (Phys. Rev. Lett. 91, 205005 (2003)) are identified to be ion cyclotron harmonic inherent kinetic theory. The derived dispersion equation is based on exact solutions of characteristic equations Vlasov a bounded cylindrical coordinate system; it different from its counterpart unbounded plasmas, provides all branches relations experiment. Positive negative ions respond potential same time scale cooperate expose orbital...
Abstract Nonlinear equations which govern the dynamics of low-frequency (ω ⪡ ω ci , where is perturbation frequency wave and ion gyro-frequency), ion-temperature-gradient-driven modes in presence equilibrium density, temperature magnetic field gradients are derived. New set nonlinear In case, new types solutions form dipolar vortices vortex streets found to exist dense quantum plasma. These structures be formed on very short spatial scales.
The linear and nonlinear dynamics of pair-ion (PI) pair-ion-electron plasmas (PIE) have been investigated in a cylindrical geometry with sheared plasma flow along the axial direction having radial dependence. coupled dispersion relation low frequency electrostatic waves has presented taking into account Guassian profile density gradient flow. It is pointed out that quasi-neutral cold inhomogeneous pure pair ion supports only obliquely propagating convective cell mode. this mode solved using...
Abstract Linear and nonlinear phenomena are investigated in toroidal ion temperature gradient (TITG)‐driven pure drift mode. The model includes inhomogeneity background magnetic field, temperature, density. Finite Larmor radius effect is incorporated to understand the of low‐frequency wave on dynamics. Electrons assumed follow nonthermal distribution, that is, kappa Cairns distributions. Dispersion relation obtained analyse linear behaviour TITG mode presence non‐Maxwellian electron...